A friend on the internet reaches out and asks you to draw her a picture, she agrees to pay the $25 fee, awesome. And it is awesome. But there are legal issues you need to think about. Are you transferring the entire copyright to the client. Do you want to limit how the image is used. Do you want to keep parts of the rights to the work? Do you want to be sure they pay, even if they magically don't like it? How many revisions do they get? These are all questions that may come up.
You're a photographer and someone saw your terrific picture on your Instagram. They want to pay you to use it. Awesome! Until you find out they want to pay you next to nothing. Well as above, a lot of considerations go into this agreement. Do they want to make a singular use of the picture? But is it in a book that will be reprinted frequently? How will you be credited, if at all? And if they don't pay, what happens?
If you are a solo consultant - whether you are a web developer, a graphic designer, a marketer, or an editor - you should absolutely have a consulting agreement. And you will always be better off if you bring your own agreement to the table rather than whatever your client provides. Though, if you are the client and are hiring a consultant, you should absolutely want a contract - whether they prepare it or not. But, if the consultant prepares the agreement, you as a client should make sure to thoroughly review it. You do not necessarily need to accept every term without question and I can help you review and negotiate potential changes.
Other Client Agreements
Every draft I've written of this has come up with other types of contracts you might enter into, but honestly there's too many. But remember, if you are selling something or buying something, the agreement should be in writing. And I'm an affordable way to keep from having to worry about it in the first place.
Do I Need A Contract?
You sign contracts everyday. Join a new social media site, contract. Bought a phone, contract. Bought a book off the internet, contract. Agreed to sell your old lawnmower to your neighbor, contract. Though not all contracts need to be in writing (you and neighbor Joe are fine). But in this wild world that is the explosion of content on the Internet, contractual questions are bound to arise. One of which is, when should you get a contract?